

body {
    height: 100vh;
    display: flex;
    background-image: url('https://p1-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/388f7a44af6b4ea3af893a1fcbfadd71~tplv-k3u1fbpfcp-watermark.image');
}

.mark {
    position: relative;
    margin: auto;
    width: 500px;
    height: 400px;
    background-color: rgba(255, 255, 255, 0.5);
    overflow: hidden;
    z-index: 10;
    line-height: 300px;
    text-align: center;
    color: #FFFFFF;
    font-size: 20px;
}
    .mark::before {
        content: "";
        position: absolute;
        background-position: top;
        filter: blur(8px);
        background-image: url($img);
        background-repeat: no-repeat;
        background-attachment: fixed;
        background-size: cover;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: -1;
    }


